They could set a maximum amount of how much you can 'bank' in a day (or count an interest on your savings). Similarly as to real banks where they limit your ISA. I would even advice that a limit should also grow with each level. This way, the game administrators will help to familiarize and teach younger generation how to save...

If you stop and think about it, it's really no diffent then members who try and spend all their all their cash in one day to avoid getting one day. You'll only be allowed to have so much so much in the bank at a time. This game is somewhat similar to Sorority Life, and that's how they did it.

Because it's so annoying to work to set yourself to work 8 hours and then have it all wiped out. (That's another thing -- let us be able to play in the arena while work, please!)